But if that's the share that supports a ballot measure before the campaign begins, it's sort of shaky, according to one seasoned political consultant.

"Obviously, something with 51 percent [support], with a good positive campaign, with almost no opposition can often win," says Floyd Ciruli of Denver's Ciruli Associates consulting firm. But after a campaign gets underway, he adds, "The 'no' tends to take over, and you will lose."

Nevertheless, polling shows that 51 percent is the slim edge Mayor John Suthers has for a proposal to impose fees on property owners to fund stormwater projects for 20 years. The measure, not yet referred to the Nov. 7 ballot by Colorado Springs City Council, was tested in a poll conducted in late June by Magellan Strategies and funded by political group Colorado Springs Forward and the Colorado Springs Chamber and EDC.

Stormwater is a tough topic. Council set up the Stormwater Enterprise in 2005 and enacted fees in 2007 without voter approval, only to defund it in 2009 after voters approved a measure to abolish it. In 2014, only 47 percent of voters favored a regional stormwater measure at the ballot box after a pre-campaign poll showed public support at 57 percent.

Now, Suthers says he needs citizens to pony up money to fund his and Council's pledge to Pueblo County to spend $460 million in the next 20 years on stormwater projects.

As outlined to poll respondents, the measure would charge residential property owners $5 a month; industrial property, $36 a month; and commercial, $26 a month. Institutional, public facilities, nonprofits and churches would pay $23 a month.

Ciruli says while it's not scientific, it's a "general truism" in the political world that a ballot measure must poll high before campaigns begin, because support can be expected to fade during the election season. He also notes that if developers, builders and contractors turn out to be the chief funders of the "vote yes" effort, it might engender skepticism.

"You just had a council race that showed developers aren't exactly running things at the moment," he says, referring to only one of five candidates backed by developers winning Council seats in the April 4 city election. "The general rule is if these things have any opposition they tend to go down." There's been no early signs of organized opposition.

The measure, as currently written, also would allow Council to raise the fees by an inflation factor starting in 2025 without voter approval. The fees would sunset in 20 years.

Expect supporters to argue that the fee is needed to remove the obligation to Pueblo County from the city's general fund, so that the city can afford to raise pay for and hire more cops and firefighters and better fund parks maintenance. It's worth noting that parks supporters have been eying a tax increase for parks funding, but so far it hasn't gotten traction.

The Magellan poll is based on feedback from 475 people and has a margin of error of plus or minus 4.5 percent.